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Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the salivary glands. Metastatic spread occurs in up to 80% of high-grade tumors and it is a strong predictor of poor outcome, however, the mechanisms underlying this process are largely unknown. Large-scale microRNA expression profiling studies of human cancers have demonstrated that dysregulation of miRNA is frequently associated with many cancer types. The aim of this study was to investigate the microRNA profile in metastatic versus non-metastatic MECs. Using Real Time RT-PCR (qPCR) we have analyzed the expression of 384 miRNAs and controls in 4 non-metastatic MECs, 3 MECs with lymph node metastasis, 3 MECs with distant metastasis, and 2 non-neoplastic human salivary gland samples. The microRNA profile was able to discriminate between non-neoplastic and tumor samples and between metastatic and non-metastatic tumors. Considering non-neoplastic samples and non-metastatic MECs, 12 microRNAs were differentially expressed. The non-neoplastic versus lymph node metastasis MEC analysis demonstrated that 10 microRNAs were differentially expressed. Considering non-neoplastic versus distant metastasis MECs, 3 microRNAs were differentially expressed: 1 down-regulated and 2 up-regulated. Comparing non-metastatic MECs versus lymph node metastasis MECs we observed 17 up-regulated microRNAs. Considering non-metastatic MECs versus distant metastasis MECs, 2 microRNAs were up-regulated. One microRNA is differentially expressed between lymph node metastasis MECs and distant metastasis MECs. Our results suggest that microRNA profiles could discriminate the metastatic potential of salivary MECs and might be helpful in diagnostic and prognostic evaluation of patients. Citation Format: Maria Eduarda S. Trevizani, Katia K. Oliveira, Fabio A. Marchi, Daniela Bizinelli, Fernanda V. Mariano, Cibele P. Nagano, Felipe A. Costa, Clóvis A. Pinto, Luiz P. Kowalski, Silvia V. Lourenço, Cláudia M. Coutinho-Camillo. microRNAs associated with metastatic potential in salivary gland mucoepidermoid carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3763.

Listeria monocytogenes is an endemic agent in the primate population at the California National Primate Research Center and has been associated with both sporadic cases and a general outbreak of pregnancy failures. The primary objective of this study was to verify the incidence of L. monocytogenes-associated abortion and fetal deaths in the Center's outdoor breeding colony. In addition, we sought to compare the group of female macaques that presented with Listeria-associated abortion with both those with nonlisteria-associated abortion and animals with successful pregnancy outcome. We calculated the incidence of L. monocytogenes-associated abortion and stillbirth by dividing the number of positive L. monocytogenes cultures from aborted fetuses by the number of pregnant female macaques from 1989 through 2009. To compare the pregnancy outcome of female macaques that have presented L. monocytogenes-associated abortion and stillbirth, we created 2 control groups: female macaques with successful pregnancy outcomes during the 1999 breeding season and animals with nonlisteria-associated pregnancy failure. These macaques were followed for 2 subsequent breeding seasons. The results showed a range in the incidence of L. monocytogenes-associated abortion and stillbirth from 0% to 8.39% throughout the 1989 to 2009 breeding seasons. In addition, the Listeria-associated abortion group did not present statistically significant differences in fertility and abortion rates when compared with the control groups. We conclude that although L. monocytogenes is an endemic agent at the Center's outdoor breeding colony, the agent's incidence varied in significance. Furthermore, an episode of L. monocytogenes-associated abortion did not affect subsequent pregnancies.

To compare the expression of proteins regulated by hypoxia between adenoid cystic carcinoma (ACC) with and without high-grade transformation (HGT). In eight ACC-HGT and 18 ACC without HGT, expression of hypoxia-inducible factor-1 (HIF-1α), vascular endothelial growth factor (VEGF), glucose transporter-1 (GLUT-1) and microvascular density (MVD) by CD105 (a hypoxia-inducible protein expressed in angiogenic endothelial cells) was determined. Expression levels of HIF-1α and VEGF as well as CD105-MVD did not differ significantly between: (i) transformed and conventional areas (TA and CA, respectively) of ACC-HGT, (ii) CA and ordinary ACC. HIF-1α was detected in 100% of cases and presented a diffuse expression pattern. No significant association was found between levels of HIF-1α expression and tumour size, metastasis and recurrence. GLUT-1 showed a prostromal expression pattern and was observed exclusively in TA (three of six cases) and in only three of 14 ACC.Both the absence of significant alterations in levels of expression of HIF-1α, VEGF and CD105 and the patterns of expression of HIF-1α and GLUT-1 suggest that hypoxia may not play a key role in the process of high-grade transformation of ACC. Although HIF-1α expression is a common finding in ACC, it cannot be used as a marker of tumour aggressiveness.